1. Field of the Invention
The application relates to a portable electronic device, and more particularly, to a portable electronic device having auxiliary input unit.
2. Description of the Prior Art
With the advancement of technology, digital goods have been miniaturized and well-integrated for daily convenience. Mobile computing and communication devices such as mobile phones, personal digital assistances (PDAs), or smart phones have gained many advantageous functions over highly integration for single device with multiple functions. In addition to the traditional numeral keypads for dialing telephone number, smart phones of next generation include message service, personal note, e-mail service, scheduling, and web browsing as extra functions, which incorporate input interfaces such as touch screen or additional QWERTY keypads for friendliness. For example, when the back cover of a smart phone slides out vertically, the exposed numeral keypads allow a user to dial a phone number as if he/she is using a common mobile phone. When the back cover slides out laterally (or the display disposed on a front cover further tilting to a specific angle relative to the horizontal plane), the exposed keypads turn out to be an easy-to-input-text QWERTY keypads.
Please refer to FIG. 1 and FIG. 2. FIG. 1 is an illustration of a sliding phone 1 according to the previous products with its back cover sliding out vertically to a specific position. FIG. 2 is an illustration of the sliding phone 1 according to the previous products with its back cover sliding out laterally to a specific position. In FIG. 1, a second member 20 slides out along the direction F to the specific position relative to a first member 10 and a first set keyboard 21 disposed on the second member 20 exposes a set of vertical numeral buttons, which are a portion of the first keyboard 21, for dialing purpose. In FIG. 2, the second member 20 slides out along the direction N to the specific position relative to the first member 10 and the first set keyboard 21 is exposed completely. For the first keyboard 21, it has different functions in different configurations, meaning that a plurality of buttons in area An in FIG. 2 are used in both the vertical and the lateral configurations. For the sake of using the symbol/context disposed on the keyboard either in vertical or lateral configuration easily, two sets of text/numeral key on the buttons in area A of said first set keyboard 21 that are readable for the vertical configuration and the lateral configuration respectively are set and cause confusion to a user in either configuration. More specifically, with only one keyboard on the traditional sliding phone, many of the buttons on the single keyboard must contain as many kinds of symbols/text as possible for necessary functions. The only way to fill in all the symbols/text in such limited button area is to reduce the size of each symbol/text for proper arrangement, which inevitably causes messy and crowded presentation and brings to the user a lot inconvenience and confusion.
There are still other kinds of sliding phones in the market that have two separated keyboards, one for the numeral keypad in vertical configuration and the other for a QWERTY keyboard in lateral configuration. Such three-tier sliding phones have at least three members including a display (disposed on the top cover), a first set keyboard (a middle component including the numeral keypads), and a second set keyboard (the back cover including the QWERTY keyboard), each member having separated inner components and circuitry respectively. Although the problem in the prior paragraphs is solved in such three-tier sliding phones, the three-member structure in such sliding phones results in more complicated circuitry, higher cost, and even thicker product size.